The CSF Evo X, Building a Time Attack Worthy 4B11 Engine Part 1

We used King’s tough XPC bearings.  We have been getting excellent results with King Bearings over the past few years and they are quickly becoming our go to favorites. Our main bearing is part number MB5722XPC and the rod bearing is part number CR4586XPC.  The XPC bearing is a tri-metal type bearing.  It has a steel backing with a lead, copper, tin intermediate layer.  The intermediate layer has a high copper content which is harder than your typical bearing alloy which gives it outstanding load capacity.  The intermediate layer is etched using the trademarked secure bond process which helps to assure adhesion to the pMax Black overlay.  The overlay is fortified with a copper nano-particles based coating which further increases load-bearing capacity while reducing friction and providing improved wear.

The main bearings feature Kings U-Groove technology with 90-degree walls on the oil feed grooves verses the typical chamfered grooves which give more bearing surface area. The oil feed holes that deliver oil to the grooves feature Kings ElliptiX oil feed hole design.  The feed holes are chamfered and lengthened to help improve the oil feed which helps assure that the rod bearings have enough oil supply. King bearings are very tightly toleranced across the bearing face so the oil clearance is consistent across the crank journal. The main and rod bearings, use King’s RadiaLock dimensioning method to get the optimal crush clearance. This helps assure that the bearings will fit tightly in their bore for good heat transfer and good resistance to spinning.  Unlike conventional bearings with tight crush,  King bearings get clamped tightly in their bores without wear near their parting line due to their dimensioning process. The bearings also use Kings Eccentrix dimensioning method which takes the oil wedge into account when designing in the bearing material thicknesses. The thickness is varied to help form a more stable and consistent hydrodynamic layer of pressurized oil on the bearings face even at high RPM.

If the crank is the heart of an engine, the cylinder head is the brain. A lot of what controls an engine’s power production is contained here. The flow of the ports and the cam specification are all about how much power your engine will produce and what sort of powerband it will have. We got our cylinder head from 4 Piston Racing.  Our head is 4 Piston’s Outlaw head package that features CNC porting, manganese bronze valve guides, and +1mm Ferrea super alloy competition Plus valves.  We also highly recommend the optional copper beryllium exhaust and nickel aluminum bronze intake valve seats, especially if you are running ethanol fuel. Ethanol has very little lubricity so it is hard on your valve seats.

The Outlaw head flows more than 60 CFM over the stock head which is a sizeable improvement. The port shapes are designed for high velocity as well as good flow so a wide powerband can be maintained, not just peak power. The valve job is done on a Newen CNC valve cutting machine for a true radius valve job.  We have found that the Newen machine valve jobs produce the most power over traditional multi angle valve jobs made with cutters or stones.

We ordered out heads with Kelford 214-C cams.  These cams have 278 degrees of advertised intake duration and 11.80mm of lift.  The exhaust cam has 272 degrees of duration and 11.35mm of lift. The duration at 1mm of lift is 236 degrees for the intake and 230 degrees for the exhaust. On our stroked engine these cams should provide peak power at around 7700-7500 rpm and have decent power till about 8000 rpm.  We used Kelford’s PACALOY beehive valve springs and titanium retainers, part number KVS11BT.  We had the cams, valvesprings and retainers cryo and WPC treated for longer life and less friction.